Shares of the troubled Canadian wireless company BlackBerry fell by more than 16 percent in pre-market trading Monday, following the collapse of an expected buyout bid from Fairfax Financial. CEO Thorstein Heins was replaced, and former Sybase CEO John Chen was named interim CEO and executive chairman.

As of 9:20 am ET, BlackBerry shares were trading at $6.48, down by $1.29. At that price, BlackBerry’s market capitalization will be about $3.4 billion when the markets open for formal trading later this morning.

That would be only slightly more than $1 billion more than the combined cash and short-term investments it said it had on hand when it reported its latest quarterly results in September. If it were to fall much farther, it would be trading at levels near or possibly below the value of its cash holdings, which would imply that the marketplace considers the company essentially worthless.

The one bit of good news, if you can call it that, is that Fairfax said it would lead an effort to inject $1 billion in cash into BlackBerry’s coffers. Fairfax itself will put in about $250 million, calling it a “vote of confidence.”